Hair removal devices of the type named above are known in the prior art. There are a large number of different hair removal devices that are designed according to different principles of operation.
Known electric shavers operate with upper and lower cutters, the upper cutter regularly being fashioned as a shaving foil and the lower cutter being fashioned as a cutter blocks. Such a cutter unit may form a short hair cutter. Through openings in the shaving foil, beard stubble passes into a space under the shaving foil and is there engaged and shaved off by the lower cutter blades. Multiple cutter units may be provided withing one shaver head arranged side by side with long hair cutter's. In addition, there are rotary shaving systems that operate according to the same principle, but use rotating lower blades.
Very often, long-hair cutters, or so-called pre-cutters, are used, with which too-long beard hairs are to be shortened before the use of the above-described short hair cutting systems, in order to improve shaving time and the shaving result. These devices are also called beard pre-cutters, beard trimmers, or the like. Whole-body hair removal devices, or feminine shavers, generally also operate according to the same principle.
In devices of the type named above, it is known that the shaving result can be improved by mechanically preparing the skin that is to be shaved, in order, for example, to lift up beard hairs.
From US 2001/0027608 A1, a shaving apparatus is known that has an edge for supporting the skin positioned in front of a cutting unit. The edge has a broad contact surface terminating in a relatively sharp edge.
The device disclosed in WO 2007/105138 A2 operates according to the same principle.
A disadvantage of these systems is that when the razor is advanced over the skin, a wave of skin is formed in front of the edge, causing tension in the skin as the razor advances, which, on one hand, can cause skin irritations and, on the other, causes a bulging of the skin oriented towards the tips of the hair while the roots of the hair are fixed in the underlying layer of skin, so that the hair is practically pulled back into the skin, which works against the cutting close to the hair root that is desirable for a thorough shave. This effect becomes greater the more firmly the razor is pressed against the skin and the softer the skin is, for example on the throat or other areas of the body. In addition, it has been shown that, due to the mechanical stress on the skin, more skin irritations occur given a larger wave of skin pushed in front of the razor.
From GB 519,367, a razor is known that has a front-positioned slotted or comb-type protective device that is intended to bring about the lifting of hairs, and which, in addition, is intended to produce a distribution of skin tension oriented transversely to the movement of direction of the razor. In the movement of direction of the razor, the skin protection device is situated in such a way that the skin is tensioned in the shape of an arc via the skin protection device and a shaving foil. A lifting and reorientation of the hairs that are to be cut is achieved via elements that produce a distribution of skin tension transverse to the direction of movement.
A disadvantage of the above-named systems is that the known comb structure proved to be too skin irriating and that the comb free guard structures proved to be too hair flatening before being cut.